Adjustable hand operator for variable stroke hydraulic pumps



June 12, 1951 s. SCHLEIN A ADJUSTABLE HAND OPERATOR FOR VARIABLE STROKE HYDRAULIC PUMPS Filed March 24, 1948 INVENTOR.

SEYMOUR SCH/.E/N BY Melt/MA. r

ATTORNEYS.

Patentecl June 12 1951 ADJUSTABLE HAND OPERATOR FOR VARI- ABLE STROKE HYDRAULIC PUllIPS Seymour Schlein, Cleveland, Ohio, assignor, by mesne assignments, to Ruger Equipment, Inc., Uhrichsville, Ohio, a corporation of Ohio Application March 24, 1948, Serial No. 16,842

9 Claims.

This application relates, as indicated, to a variable stroke hydraulic pump and more particularly to a hand operated pump wherein both the length of stroke and the power required may be adjusted without interruption of the pumping operation.

There are innumerable forms of hydraulic pumps and mechanisms for operating the same. In recent years there has been an increasing use of hydraulic fluid pressure operated cylinders to actuate many devices and frequently it is necessary to provide such fluid pressure by means of a hand operated pump. One such use is in a portable fioor crane having a pivoted boom which is raised and lowered by means of a hydraulic cylinder. Since the power source (human labor) is of limited capacity, it is important to provide a pump which may be quickly adapted to the load being lifted. On the other hand, the chief advantage of such portable cranes and the like lies in their being promptly available for a variety of miscellaneous jobs without the necessity of elaborate adjustment.

It is, therefore, a principal object of my invention to provide novel means for varying the stroke of a reciprocable member such as a pump plunger while at the same time changing the power required to operate the same.

A further object is to provide such mechanism employing a minimum of parts and utilizing the same means to permit both adjustment and necessary lost motion.

Another object is to provide such adjusting means which may be regulated by the operator without interrupting operation of the pump.

Other objects and advantages will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, said invention then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawing setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention may be employed.

In the said annexed drawing:

Fig. 1 is a side elevational View, partly in section, of my new adjustable pump operating means;

Fig. 2 is an end elevational view thereof;

Fig. 3 is a fragmentary detail view showing the adjusted position for minimum stroke; and

Fig. 4 is a fragmentary detail view of a modified form of fulcrum pivot means.

Referring now more particularly to said drawing, a double acting piston-cylinder pump is there illustrated comprising a cylinder l with cylinder heads 2 and 3, through the latter of which passes cylindrical piston or plunger 4. Such piston is provided with a piston head 5 fitting within cylinder l and havin an axial opening closed by a check-valve 1. Ports 8 and 9 serve to place the inner portion of piston 4 in communication with the interior of cylinder I. Fluid inlet is through conduit [0 and cylinder head 2, a checkvalve l l closing the passage within such cylinder head. Fluid outlet is by way of conduit l2 and cylinder head 3.

In operation, as piston 4 moves from left to right as shown in Fig. 1 check-valve I will be held closed and piston head 5 will force fluid through outlet l2. Simultaneously, fluid will be drawn past check-valve I l and into the cylinder behind the moving piston head. On the return stroke, valve II will be closed and valve I opened, causing displaced fluid within the cylinder to flow through valve 1 andports 8 and 9 to outlet I2. The pump therefore is double acting and fluid is delivered at all times during operation.

The position of the piston-cylinder assembly about its axis is, of course, a matter of choice, and in Figs. 1 and 3 is shown turned from that shown in Fig. 2, to facilitate showing the arrangement of the parts. While the adjusting means of this invention is very advantageously. employed with this type of pump, it will be understood that it is suitable for use in conjunction with a wide variety of other pumps, as may be desired.

The pump assembly is mounted between side frame plates l3 and M as by welding or by means of bolts such as l5 and l 6. A pair of spaced vertically disposed bars I! and !8 are welded to the inner faces of each of such plates to provide opposed guide-ways to receive fulcrum pivot pin I 9. Such pin is transversely secured in the head 7 29 of upwardly extending screw member 2! to the other end of which a tubular extension 22 of tubular handle 23 is threaded. A sleeve 24 encloses and supports such extension and handle for relative rotation and is held against relative axial movement by shoulder 25 and washer 26. Handle 23 is secured to extension 22 for rotation therewith.

Arms 21 and 28 extending from the end of piston 4 form a yoke embracing sleeve 24 and pivotally secured thereto at 29. Such yoke, as shown, is rigid with the piston against movement in a vertical plane but may swivel slightly in a horizental plane to accommodate itself to the sleeve.

The method of adjusting the operation of the pump now becomes apparent. Referring particularly to Fig. 1 of the drawing, it will be seen that handle 23 may be rocked back and forth about pivot pin I9 to reciprocate piston 4 for a full stroke; i. e., the handle may be rocked to the dot and dash line position. Pin 19 will ride up and down slightly in the vertical guide-ways between members H and [8 to reconcile the arcuate movement of the handle and the straight-line movement of the piston to which it is secured.

When it is wished to reduce the stroke of the piston and the power which need be applied, handle 23 will be rotated about its axis to draw in screw 2! and thereby elevate the position of ful crum pin I9. When in the uppermost position as shown in Fig. 3, the stroke is obviously very short and the leverage exerted very great. Any intermediate position may be selected. It will be observed that the device is very flexible, enabling the operator, while actively rocking the handle, to watch a pressure gauge or the like and instantly adjust the output and power required merely by rotating such handle and without any interruption of his work.

Referring now to Fig. 4 of the drawing, there is there illustrated an alternative form of fulcrum pivot means which may be employed in accordance with my invention. Here, the threaded stem or screw portion 38 of the lever is integral with the handle and a nut 31 provided with studs 32 to fit in the vertical guideways is employed instead of head to which it corresponds. As a result, when the handle is turned such nut is caused to move either up or down in the guideway, thereby altering both the length of stroke of the piston and the power required to be exerted to operate the lever. Usually the Fig. 1 construction will be preferred, however, since the threaded portion may be drawn into the hollow handle whereas in the Fig. 4 arrangement the end of the threaded portion will sometimes extend a certain distance through nut 3|, requiring clearance.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

I therefore particularly point out and distinctly claim as my invention:

1. Adjustable means for reciprocating the piston of a double acting piston-cylinder pump comprising spaced side frame members, vertically extending opposed guide-ways carried by said frame members, an extensible hand lever comprising upper and lower sections, such lower section being threaded into such upper section and having a transverse pin through its lower end, the respective ends of such pin fitting in said guide-ways and serving both to hold such lower lever section against axial rotation and as a fulcrum pivot for said lever, a sleeve around such upper lever section secured against relative axial movement, and a yoke extending from such piston and pivotally attached to said sleeve, whereby, by rotating such upper lever section such lower section may be extended or drawn in to correspondingly shift the position of such fulcrum pin in said guide-ways and accordingly alter both the length of stroke of such piston and the power required to be exerted.

2. Adjustable means for reciprocating the piston of a piston-cylinder pump comprising spaced .4 parallel side frame members, vertically extending opposed guide-ways carried on the respective inner faces of said members, an extensible hand lever comprising an upper tubular section and a lower section threaded into said upper section and having a transverse pin through its lower end, the respective ends of such pin fitting in said guide-ways and serving both to hold said lower section against axial rotation and as a fulcrum pivot for said lever, a sleeve around said upper lever section secured against relative axial movement, and a yoke extending from such piston and pivotally attached to said sleeve, whereby, by rotating said upper lever section said lower lever may bedrawn in or extended to correspondingly shift the position of such fulcrum pin up or down in said guide-ways and accordingly alter both the length of stroke of such piston and the power required to be exerted to operate said lever.

3. Adjustable means for reciprocating the piston of a piston-cylinder pump comprising a vertically disposed guide-way, a hand lever comprising an upper tubular section and a lower section threaded into said upper section and having a transverse portion formed to fit in said guideway serving both to hold said lower section against axial rotation and as a :fulcrum pivot for said lever, means pivotally connecting said piston to said upper section of said lever about an axis parallel to such fulcrum pivot, and means restricting axial movement of said upper section of said lever relative to said connecting means but permitting relative rotative movement. whereby, by rotating said upper section of said lever said lower section of said lever may be drawn in or extended to correspondingly shift the position of such fulcrum pivot up or down said guide-way and accordingly alter both the length of stroke of such piston and the power required to be exerted to operate said lever.

4. Adjustable means for reciprocating the piston of a piston-cylinder pump comprising a guide-way, a lever comprising a handle portion and an axial extension threadedly joined thereto, means pivotally connecting said handle portion and such piston, said handle means being mounted for axial rotation relative to said connecting means but restricted against movement axially relative thereto, and means on said lever extension engaged in said guide-way to serve as a fulcrum pivot for said lever, whereby, by rotating said handle portion said extension of said lever may be drawn in or extended as desired to correspondingly shift the position of said fulcrum pivot up or down said guideway and ac cordingly alter both the length of stroke of such piston and the power required to be exerted to operate said lever.

5. Lever means pivotally attached to a reciproca ble member for reciprocating the same comprising a guide-way, a handle portion, an axial extension of said handle portion threadedly joined thereto, means holding said extension against axial rotation, means pivotally connecting said handle portion and said reciprocable member, said handle portion being mounted for axial rotation relative to said connecting means but restricted against movement axially relative thereto, and means on said lever extension engaged in said guide-way to serve as a fulcrum pivot for said lever, whereby, by turning said handle portion, said fulcrum pivot may be moved toward or away from such point of pivotal connection with said reciprocable member.

6. Lever means pivotally attached to areciprocable member for reciprocating the same, comprising a guide-way, an upper lever portion and a lower lever portion threadedly connected for relative axial adjustment, means holding said lower portion against axial rotation, means pivotally connecting said upper portion and said reciprocable member, said upper portion being mounted for axial rotation relative to said connecting means but restricted against movement axially relative thereto, and means on said lower portion engaged in said guide-way to serve as a fulcrum pivot for said lever, whereby, by turning said upper portion, said fulcrum pivot may be moved toward or away from such point of pivotal connection with said reciprocable memher.

7. Adjustable means for reciprocating the piston of a hand-operated piston-cylinder pump comprising a lever having a handle portion for manually rocking the same, a fulcrum pivot member threadedly connected with said handle portion for relative axial adjustment, means pivotally connecting said lever and such piston, I

said handle portion being mounted for rotation about its axis relative to said latter connecting means but held against relative movement axially thereof, and a straight guideway fixed with respect to the cylinder of such pump having said fulcrum pivot member engaged therein, said guideway thus permitting straight-line reciprocation of said fulcrum pivot member while holding the same against rotation about the axis of said lever, whereby, by rotating said handle portion, the fulcrum pivot may be shifted along such straight line path of said guideway toward and away from such point of pivotal connection of said lever with such piston.

8. Adjustable means for reciprocating the piston of a hand-operated piston-cylinder pump comprising a lever having a handle end for manually rocking the same, a straight guide-way fixed with respect to the cylinder of such pump, a fulcrum pivot member for said lever engaged in said guide-way, means pivotally connecting said lever and such piston, and screw means rotatable by rotation of said handle end of said lever about the axis of said lever adapted to shift said fulcrum pivot member along said straight guide-way toward and away from such point of pivotal connection of said lever and such piston.

9. Adjustable means for reciprocating the piston of a hand-operated piston-cylinder pump comprising a lever having a handle end for manually rocking the same, a guide-way fixed with respect to the cylinder of such pump, a fulcrum pivot member for said lever engaged in said guide-way, means pivotally connecting said lever and such piston, and screw means rotatable by rotation of said handle end of said lever about the axis of said lever adapted to shift said fulcrum pivot member along said guide-way toward and away-from such point of pivotal connection of said lever and such piston.

SEYMOUR SCHLEIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 216,752 Olsen June 24, 1879 536,430 Higgins Mar. 26, 1895 552,387 Moffatt Dec. 31, 1895 678,172 Grist July 9, 1901 976,148 Caps Nov. 22, 1910 991,802 Robinson May 9, 1911 1,147,893 Robson July 27, 1915 2,092,738 Rodgers Sept. 7, 1937 2,197,730 Mugford Apr. 16, 1940 2,436,916 Copeland Mar. 2, 1948 

